MIKE 21 BW, User Manual, Page: 125 / 196

Calibration Parameters
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the correct height of the still water level, i.e. the model reference level, rela-
tive to the datum used in setting up your bathymetry, see the figure below.
This is done by specifying the Shift of Reference Level. Then, the model will
automatically make any internal adjustments necessary for that particular
model simulation. In this way it is possible to carry out model simulations
using a range of different water levels, without having to alter the bathymetry.
NOTE: When using the Shift of Reference Level option (in the Calibra-
tion/Bathymetric Parameters dialog) you should remember also to change
the input wave data as the water depth at the generation lines change
accordingly to the change in water level.
Often the 'safest' thing to do is to make new (copies) of the bathymetry files
and change the depths in the different bathymetry files.
Figure 5.12 Example of shifting the reference level
Example
As an example, consider a bathymetry created using LAT as datum. You wish
to run a simulation for mean sea level (MSL). The MSL is 1.0m above LAT, so
you s1.0m as shift of reference level. At a point where the bathymetry
bed level is –7.0m, the total water depth becomes
-(-7.0m) +1.0m = 8.0m.
5.3.2 Boundary data
At an open boundary the incident waves are specified as time series of sur-
face elevations, or flux densities, perpendicular to the boundary. If the Deep
Water Terms are included, the time series of the surface curvature or the sur-
face slope must also be specified.
The input data files can be given as a time series (i.e. dfs0) or a line series
(.dfs1)